检索结果-内蒙古大学图书馆

Mitigating Multiple Moving Interferers With the Hybrid Double Zero MVDR Beamformer

IEEE ACCESS 2024年 12卷 111206-111217页

作者： Erdim, Savas Buck, John R. Univ Massachusetts Dartmouth Dept Elect & Comp Engn Dartmouth MA 02740 USA

Interferers with a high bearing rate challenge the ability of the minimum variance distortionless response (MVDR) beamformer to place accurate notches in the direction of the interferer. Consequently, the MVDR notch location always slightly lags the interferer's actual location, degrading the MVDR's ability to suppress moving interferers. Creating a flatter and broader notch is a more effective approach to dealing with the interferer's motion. This paper proposes a hybrid double zero (HDZ) MVDR beamformer that generalizes the double zero (DZ) MVDR beamformer proposed by Tuladhar and Buck in 2015. The DZ MVDR beamformer constraints the array polynomial to be the square of a lower-order polynomial so that all beampattern notches are second-order roots of the array polynomial. However, constraining every notch to be a second-order notch reduces the degrees of freedom (DoF) available for background white noise attenuation. In contrast to the DZ beamformer, the HDZ beamformer factors the beampattern into adaptive and fixed components. The adaptive component has wide notches to suppress moving interferers, while the fixed component improves the white noise gain (WNG) and ensures the array weight vector length matches the array size. The HDZ beamformer spends fewer DoFs on adaptive nulling than the original DZ beamformer, freeing more DoFs for WNG. Simulations and microphone array experiment results show that the HDZ beamformer outperforms the competing beamformers in terms of array output power and WNG.

关键词： Sensor arrays Vectors Covariance matrices polynomials array signal processing White noise Narrowband Adaptive beamformer (ABF) minimum variance distortionless response beamformer (MVDR) second-order notch multiple interferers moving interferer double zero MVDR beamformer array polynomial

来源：评论

学校读者我要写书评

暂无评论

A Hybrid Double Zero MVDR Beamformer That is Universal Over the Number of Second Order Notches

引用

IEEE ACCESS 2024年 12卷 195575-195588页

作者： Erdim, Savas Buck, John R. Univ Massachusetts Dartmouth Dept Elect & Comp Engn Dartmouth MA 02740 USA

In a dynamic environment, close-range and fast-moving interferers transit the resolution cells rapidly, challenging the minimum variance distortionless response (MVDR) beamformer's ability to place accurate notches in each interferer's direction. One common approach to overcome this problem is to apply a broader or wider notch at the interferer location. The hybrid double zero (HDZ) MVDR beamformer is a simple and robust method to form a wider notch by implicitly generating second-order notches in the beampattern. The HDZ beampattern is a product of adaptive and fixed factors. The adaptive component has wide second-order notches to suppress moving interferers, while the fixed component improves the white noise gain (WNG) and ensures the array weight vector length matches the array size. However, the challenge for the HDZ beamformer is choosing the ideal number of second-order notches to suppress the moving interferers in a dynamic environment. In practice, the number of moving interferers is unknown and may also change over time. Therefore, an HDZ beamformer with a fixed number of second-order notches may not effectively suppress all the moving interferers if the number of interferers surpasses the number of second-order notches. The need for a time-varying number of second-order notches leads us to design a universal HDZ (UHDZ) beamformer that is universal over this parameter. The UHDZ beamformer rivals the best beamformer in a set of HDZ beamformers with a fixed number of second-order notches without needing prior knowledge of the number of moving interferers or the environment. This paper evaluates the performance of the UHDZ beamformer in simulations and microphone array experiments that include multiple moving interferers.

关键词： Vectors Sensor arrays Covariance matrices array signal processing White noise Narrowband Spatial resolution polynomials Direction-of-arrival estimation Attenuation Minimum variance distortionless response beamformer MVDR adaptive beamformer second-order notch multiple interferers moving interferer double zero MVDR beamformer array polynomial universal algorithm

来源：评论

学校读者我要写书评

暂无评论

Unit Circle Rectification of the Minimum Variance Distortionless Response Beamformer

引用

IEEE JOURNAL OF OCEANIC ENGINEERING 2020年第2期45卷 500-510页

作者： Tuladhar, Saurav R. Buck, John R. Univ Massachusetts Dartmouth Dept Elect & Comp Engn Dartmouth MA 02747 USA ARCON Corp Waltham MA 02451 USA

The sample matrix inversion (SMI) beamformer implements Capon's minimum variance distortionless (MVDR) beamforming using the sample covariance matrix (SCM). In a snapshot limited environment, the SCM is poorly conditioned resulting in a suboptimal performance from the SMI beamformer. Imposing structural constraints on the SCM estimate to satisfy known theoretical properties of the ensemble MVDR beamformer mitigates the impact of limited snapshots on the SMI beamformer performance. Toeplitz rectification and bounding the norm of weight vector are common approaches for such constraints. This paper proposes the unit circle rectification technique which constrains the SMI beamformer to satisfy a property of the ensemble MVDR beamformer: for narrowband planewave beamforming on a uniform linear array, the zeros of the MVDR weight array polynomial must fall on the unit circle. Numerical simulations show that the resulting unit circle MVDR (UC MVDR) beamformer frequently improves the suppression of both discrete interferers and white background noise compared to the classic SMI beamformer. Moreover, the UC MVDR beamformer is shown to suppress discrete interferers better than the MVDR beamformer diagonally loaded to maximize the signal-to-interference-plus-noise ratio.

关键词： Electronic countermeasures Sensors array signal processing Narrowband Signal to noise ratio Covariance matrices Linear systems Adaptive beamformer (ABF) array polynomial Capon beamformer minimum variance distortionless response (MVDR) unit circle

来源：评论

学校读者我要写书评

暂无评论

Design of Linear Phased array for Interference Suppression Using array polynomial Method and Particle Swarm Optimization

引用

WIRELESS PERSONAL COMMUNICATIONS 2012年第2期63卷 501-513页

作者： Abu-Al-Nadi, D. I. Ismail, T. H. Al-Tous, H. Mismar, M. J. Univ Jordan Dept Elect Engn Amman Jordan Al Ahliyya Amman Univ Dept Elect & Commun Amman Jordan Princess Sumaya Univ Technol Dept Elect Engn Amman Jordan

In this work, a linear phased array pattern design with null steering is achieved using the array polynomial technique and the Particle Swarm Optimization (PSO) algorithm. The null steering for interference suppression is obtained by controlling some of the roots on the Schelkunoff's unit circle while keeping the roots responsible for the main beam unchanged. The rest of the roots are controlled to minimize the Side Lobe Level (SLL) of the array pattern using the PSO algorithm. It has been demonstrated that this technique achieved more than 50% reduction in the parameters needed to be optimized compared with the conventional complex coefficients optimization techniques. Consequently, the fitness function is only responsible for the SLL as the prescribed controlled nulls and the mainbeam characteristics are solved analytically. The simulated results show the effectiveness of the proposed technique.

关键词： Linear phased arrays Null steering array polynomial Pattern synthesis PSO

来源：评论

学校读者我要写书评

暂无评论

Unit circle MVDR beamformer 40

Unit circle MVDR beamformer

引用

40th IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2015

作者： Tuladhar, Saurav R. Buck, John R. University of Massachusetts Dartmouth Electrical and Computer Engineering Department North DartmouthMA United States

ISBN: (纸本)9781467369978

The array polynomial is the z-transform of the array weights for a narrowband planewave beamformer using a uniform linear array (ULA). Evaluating the array polynomial on the unit circle in the complex plane yields the beampattern. The locations of the polynomial zeros on the unit circle indicate the nulls of the beampattern. For planewave signals measured with a ULA, the locations of the ensemble MVDR polynomial zeros are constrained on the unit circle. However, sample matrix inversion (SMI) MVDR polynomial zeros generally do not fall on the unit circle. The proposed unit circle MVDR (UC MVDR) projects the zeros of the SMI MVDR polynomial radially on the unit circle. This satisfies the constraint on the zeros of ensemble MVDR polynomial. Numerical simulations show that the UC MVDR beamformer suppresses interferers better than the SMI MVDR and the diagonal loaded MVDR beamformer and also improves the white noise gain (WNG). © 2015 IEEE.

关键词： adaptive beamformer array polynomial MVDR

来源：评论

学校读者我要写书评

暂无评论

Unit circle MVDR beamformer

Unit circle MVDR beamformer

引用

IEEE International Conference on Acoustics, Speech and Signal Processing

作者： S. R. Tuladhar J. R. Buck Electr. & Comput. Eng. Dept. Univ. of Massachusetts Dartmouth Dartmouth MA USA

ISBN: (纸本)9781467369985

关键词： MVDR adaptive beamformer array polynomial Unit circle Zero polynomial Structure of Managed Information Logic arrays

来源：评论

学校读者我要写书评

暂无评论

Analytical array polynomial method for linear antenna arrays with phase-only control

引用

AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2007年第7期61卷 485-492页

作者： Mismar, M. J. Ismail, T. H. Abu-Al-Nadi, D. I. Princess Sumaya Univ Technol Dept Elect Engn Amman Jordan Al Ahliyya Amman Univ Dept Elect & Commun Amman Jordan Univ Jordan Dept Elect Engn Amman Jordan

A new analytical synthesis technique is developed for the phase-only control of linear antenna arrays and is based on the Schelkunoff's unit circle. The array factor is formulated as an array polynomial in the complex z-plane and as a product of corresponding subpolynomials such that their roots are located on the unit circle. A constraint is derived such that the expansion of the subpolynornials yields current excitations with unity magnitudes. In general, the constraint of phase-only control forces some element excitations to be zero for an arbitrary number of array elements. The subpolynomial with the largest degree is used to synthesize the main beam characteristics. The null steering for interference suppression is obtained by using only one subpolynomial to steer only one null. The results verify the developed analytical solution to synthesize the prescribed patterns using the phase shifters of the linear antenna arrays. (c) 2006 Elsevier GmbH. All rights reserved.

关键词： linear arrays pattern synthesis null steering array polynomial

来源：评论

学校读者我要写书评

暂无评论

PATTERN SYNTHESIS WITH PHASE-ONLY CONTROL USING array polynomial TECHNIQUE

PATTERN SYNTHESIS WITH PHASE-ONLY CONTROL USING ARRAY POLYNO...

引用

IEEE International Conference on Signal Processing and Communications

作者： Mismar, M. J. Abu-Al-Nadi, D. I. Ismail, T. H. Princess Sumaya Univ Technol Dept Elect Engn Amman Jordan Univ Jordan Dept Elect Engn Amman Jordan Al Ahliyya Amman Univ Dept Elect & Commun Amman Jordan

ISBN: (纸本)9781424412358

A new synthesis technique using the phase shifters of the linear array elements is developed using the array polynomial technique. The array factor is expressed as the product of subpolynomials such that their roots are located on the unit circle. All array elements are active for any arbitrary non-prime number of the array elements. The results show that the developed method in the form of an analytical solution can synthesize the prescribed patterns using the phase shifters of the linear antenna arrays.

关键词： array polynomial Pattern Synthesis Linear arrays

来源：评论

学校读者我要写书评

暂无评论

REDUCING THE EFFECT OF POINTING ERRORS ON THE PERFORMANCE OF AN ADAPTIVE array

引用

ELECTRONICS LETTERS 1990年第20期26卷 1646-1647页

作者： LO, KW Dept. of Electron. Eng. Hong Kong Polytech. Kowloon Hong Kong

The effect of pointing errors on the performance of the directional constrained adaptive array using symmetric amplitude control can be reduced by correcting the zeros of the array polynomial. The effect can be further reduced by adding an extra pair of zeros to the array polynomial. Examples are given to illustrate the effectiveness of these methods.

关键词： adaptive array antenna phased arrays antenna theory array polynomial directional constrained adaptive array effect of pointing errors extra pair of zeros symmetric amplitude control

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：